In a multi-display system where a plurality of display devices are connected to each other, a control command for controlling each display device is executed by connecting a personal computer (PC). In detail, the plurality of display devices may be connected in a daisy chain type and connected to the PC, or each of the plurality of display devices may be connected to the PC and may receive a control command from the PC to perform an operation corresponding to the control command.
There is a preferable case where like a time synchronization command among control commands transmitted to the display devices, a matter set in one display device is applied to another display device as-is, and in this case, a connection of a PC is not necessary. However, even in this case, there is inconvenience where a PC should be connected to the multi-display system for synchronizing a time of the display devices as illustrated in FIG. 1A.
There is a method where even without connecting a PC to the multi-display device, a control command such as a direct time synchronization command is transferred from a display device, acting as a master, to a display device acting as a slave.
In order for the master to directly transfer a control command to the slave, as illustrated in FIG. 1B, there is inconvenience where a connection between an OUT port of the master and an IN port of the slave should be changed from an IN port of the master to an IN port of the slave whenever the control command is transferred.
Moreover, in a case of connecting the IN port of the master to the IN port of the slave, since it is unable to connect the master and a PC, there is inconvenience where the PC issues a control command to the display devices, or it is unable to check a state of a display device.